Dragons’ Den goes back to basics in a student-oriented edition that teaches, among other things, that there’s no substitute for hard work and doing your homework when it comes to a credible business proposition.

It’s a measure of just how smart and witty Republic of Doyle has become that, when gun-toting baddies ask Allan Hawco’s Jake Doyle, “Where’s Carlos?” in Wednesday’s fifth-season opener, he resists the temptation to go for a cheap laugh, even though he’s in serious danger.

Circumspect but not chastened: If Simon Cowell seems more humble than he did two years ago, when he loudly proclaimed The X Factor would take North American television by storm, the way it had in the U.